Bulletin of the National Research Centre (Jul 2020)
Influence of insect traps and insecticides sequential application as a tactic for management of tomato leafminer, Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae)
Abstract
Abstract Background Tomato crop, Lycopersicon esculentum L. (Solanaceae), usually attacked by many insect species, including the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), where its larvae cause damage up to 80–100% by due to its feeding habits by making tunnels in all tomato parts. The influence of insect traps application and insecticides sequential as a tactic for T. absoluta management was carried out. Results Sex pheromone and sticky traps were used for mass trapping this pest; sex pheromone traps were more effective than the sticky one; the number of caught insects was higher in the untreated plots than the treated one. Also, the general mean number of captured insects by sex pheromone traps was 432.89 and 633.40 (vegetative stage) and 691.3 and 1865.5 (fruiting stage) adults/trap/week, for treatment and control, respectively. When the first infestation appeared, the non-conventional insecticides were consecutively sprayed once/week for 3 weeks with the following order: Radiant, Coragen, and Emperor (during the vegetative stage). After that, the formulated essential oils Nimbecidine (commercial) and Rosa (prepared) were respectively sprayed twice/week for 2 weeks (during the fruiting stage). The general average of reduction in infestation reached 95.81% when non-conventional insecticides were used, while it reached 92.15% when the formulated essential oils were used. Finally, at the end of the experiment, promising mean reduction in infestation reached 93.98% was achieved. Yield of marketable healthy fruits was recorded and expressed as ton/feddan. Treatments gave significantly higher yield over untreated control. The tomato yield reached 28.25 t/fed. compared with control (8.35 t/fed.), which gain 19.94 t/fed. equal to 238.32% more than the untreated control. Conclusions The results indicated that insect traps and insecticides sequential application as a tactic for management T. absoluta were more effective; the rotation of insecticides avoid build up resistance and achieved satisfied reduction (93.98%) in the infestation and high yield production.
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